Steve Hargreaves - Moderator Posted October 16, 2007 Share Posted October 16, 2007 Up to now I've always managed to measure current on my flight packs with my 20A multimeter but the latest project is going to go over that so it seems a watt meter is required.Anyone got any thoughts on what to get? Most shops seem to offer the Tornado unit at about £35....any good or are there better ones out there? I don't want to spend a fortune but in order to keep the magic smoke at bay & stop Grumpy Myron thinking the only accessory you need for e-flight is a fire extinguisher I think some idea of currentflow is essential..... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 16, 2007 Share Posted October 16, 2007 Well your correct about the need for one. I have had back luck with Tornado stuff, and after 2 ESCs let out the magic smoke whilst under their maximum capacity, I vowed to not buy any more Tornada stuff. I use an Astro Flight "Whattmeter" and it has been very good for the 3 years I have owned it.They are now down in price too, - I paid around 70 quid in those days. Quote Link to comment Share on other sites More sharing options...
Mouldy Posted October 16, 2007 Share Posted October 16, 2007 Just bought a Tornado meter.... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 16, 2007 Share Posted October 16, 2007 Well perhaps one of the following two things is applicable .....1) Compared to an ESC, the meters are fairly simple devices and the underpaid and overworked 10 year old orphans might actually know how to assemble them correctlyor......2) Tornada branded stuff generally has actually improved over the last couple of years.... ( or hopefully both ! ) I hope so - good luck! Quote Link to comment Share on other sites More sharing options...
Mouldy Posted October 16, 2007 Share Posted October 16, 2007 Which begs another quesition to which I think I know the answer.....Does the meter go between the battery and the esc or the esc and the motor? My gut feeling is that it dosent matter........... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 16, 2007 Share Posted October 16, 2007 Actually yes it does..it goes between the battery and the ESC, because the ESC itself will draw some current and affect the on load V of the battery somewhat. Quote Link to comment Share on other sites More sharing options...
Mouldy Posted October 16, 2007 Share Posted October 16, 2007 doh...Ill get me coat! Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted October 16, 2007 Author Share Posted October 16, 2007 Mouldy, as a watt meter (in this case) is for DC I would be seriously impressed if you could connect it between the ESC & the motor......I think you'd have a couple of wires spare & some very interesting readings!!!!Others have mentioned the Astro unit but I can't find a source....Then theres those Felagio or Fellatio meters that Robotbirds sell..... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 17, 2007 Share Posted October 17, 2007 yes another very good reason Steve !! LOLhttp://www.astroflight.com/store/store-type-tem.html?item=products:af-101n&sid=0001mzCKLIyL1BAotE5m9R0I know its the Staes, but at the current exchange rate - not a bad price. I got mine direct a few years back.Try West London models...I believe they are stocking them ? http://www.westlondonmodels.com/product1836/Astro-Super-Whattmeter/ Quote Link to comment Share on other sites More sharing options...
Mouldy Posted October 17, 2007 Share Posted October 17, 2007 You ever get one of those moments where you engage mouth before brain? well in this instance fingers before brain.....read posts above!!!! (Because I did exactly that!!!) Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 17, 2007 Share Posted October 17, 2007 EVERYONE gets those moments - especially so-called important and clever folk like US presidents! Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted October 18, 2007 Author Share Posted October 18, 2007 I tried West London models...no wonder I couldn't find it...they spell it WHatt meter!!!Shorely Shome Mishtake....Watts is watts not whatts......at least they were when I did O level Physics!!! Quote Link to comment Share on other sites More sharing options...
Mouldy Posted October 19, 2007 Share Posted October 19, 2007 Shorely Shome Mishtake? Tony Benn in the house??? Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted October 19, 2007 Share Posted October 19, 2007 In Cornwall we say Wos on boy! Now I know wot they were talking about I think ! Sorry Just having a pre breakfast brain problem .Now where did I put that breakfast glass ? Quote Link to comment Share on other sites More sharing options...
Guest Posted October 19, 2007 Share Posted October 19, 2007 anyone any comments on the "Watts up meter" ? I was considering that or tornado John Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 19, 2007 Share Posted October 19, 2007 " I tried West London models...no wonder I couldn't find it...they spell it WHatt meter!!! "Thats because that is "What" it is called ...Astro Bob ( the designer and guru of Astro flight in the US ) thought he would have a small play on words, as the meter measures "what" your powertrain is doing, including a display of Watts. Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 20, 2007 Share Posted October 20, 2007 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Myron Beaumont Posted October 20, 2007 Share Posted October 20, 2007 I'm confused by you 'lectric gurus again .H ow the hell do you measure Watts on one meter .I was tought (correctly) that amps X volts =watts SO you need two measurements _yes or no _? Amperes ( current) are measured in line with the current flow ie in circuit whereas voltage (Potential difference) is measured across a component or a source of power Has someone invented something with four terminals I've not heard about (wouldn't be the first time) Guess who? Quote Link to comment Share on other sites More sharing options...
Guest Posted October 20, 2007 Share Posted October 20, 2007 Myron,you are correct - 2 meters needed for measuring watts. I assume that in the tornado and "watts up meter" that the internal circuitry can measure both volts and amps and then displays on digital readout ( ie not an analgue meter) both values and software does rest to show instant power -watts- and cumulative power - watthour.I am still hopeful thaat someone can comment on the Watts Up meter to let me evaluate it against the tornado comments earlier, since from what I have read so far re motor/battery/prop/thrust, wattmeters would appear to be essential to get best out of power trainJohn Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 20, 2007 Share Posted October 20, 2007 Yes John....the inline "wattmeter" style devices ( and they all do pretty much the same thing irrespective of brand name and price-points - I am sure the watts up meter will be fine ) do exactly that, and most if not all of them do the computation for you ( amps X volts ) and give a third readout display of watts. The other nice thing is that as you are seeing a real time on load voltage of your battery, you can watch to see how it holds up under stress as you whack the throttle open for short bursts. Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 22, 2007 Share Posted October 22, 2007 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted October 22, 2007 Author Share Posted October 22, 2007 Yeah...the main thing is the current Eric.....thats whats gonna kill yer components & very few meters go over 10 amps. In EF you get to 20A pretty quickly & even something around 40-45" span can be pulling in excess of 40A which is a whole lot of current & will release a lot of magic smoke if the ESC/Motor/Battery ain't up to it. Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 23, 2007 Share Posted October 23, 2007 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted October 24, 2007 Author Share Posted October 24, 2007 Yes I spotted that Eric.....is this a "Clamp Meter"...the sort with two "pincers" that you put around the cable? How well does it work & is it accurate (ie have you checked the results with an in-line ammeter)? I'm interested to know how these things work with our systems.......especially since we use such small wires for such huge currents...I know most electrical engineers would go white at how much current we pass through such small diameter wire...... Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 24, 2007 Share Posted October 24, 2007 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
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